import webpush from "web-push";
import type { ApprovalType } from "@prisma/client";

import { approvalLabel } from "@/lib/domain";
import prisma from "@/lib/prisma";

type PushTargetExpense = {
  id: string;
  title: string;
  amount: number;
};

function configureWebPush() {
  const publicKey = process.env.NEXT_PUBLIC_VAPID_PUBLIC_KEY;
  const privateKey = process.env.VAPID_PRIVATE_KEY;
  const subject = process.env.VAPID_SUBJECT;

  if (!publicKey || !privateKey || !subject) {
    return false;
  }

  webpush.setVapidDetails(subject, publicKey, privateKey);
  return true;
}

export function getApprovalRole(approvalType: ApprovalType) {
  switch (approvalType) {
    case "CHAIR_A":
      return "ORGA";
    case "CHAIR_B":
      return "BOARD";
    case "FINANCE":
      return "FINANCE";
  }
}

export async function notifyApprovalRequest(expense: PushTargetExpense, approvalTypes: ApprovalType[]) {
  if (!configureWebPush() || approvalTypes.length === 0) {
    return;
  }

  const roles = approvalTypes.map(getApprovalRole);
  const subscriptions = await prisma.pushSubscription.findMany({
    where: {
      user: {
        role: {
          in: roles
        }
      }
    },
    include: {
      user: {
        select: {
          role: true
        }
      }
    }
  });

  await Promise.all(
    subscriptions.map(async (subscription) => {
      const approvalType = approvalTypes.find((type) => getApprovalRole(type) === subscription.user.role);
      const payload = JSON.stringify({
        title: "Freigabe angefragt",
        body: `${expense.title} (${expense.amount.toFixed(2)} EUR) braucht ${approvalType ? approvalLabel(approvalType) : "deine Freigabe"}.`,
        url: `/?expense=${encodeURIComponent(expense.id)}`,
        tag: `approval-${expense.id}-${subscription.user.role}`
      });

      try {
        await webpush.sendNotification(
          {
            endpoint: subscription.endpoint,
            keys: {
              p256dh: subscription.p256dh,
              auth: subscription.auth
            }
          },
          payload
        );
      } catch (error) {
        const statusCode = typeof error === "object" && error && "statusCode" in error ? error.statusCode : null;

        if (statusCode === 404 || statusCode === 410) {
          await prisma.pushSubscription.delete({
            where: {
              endpoint: subscription.endpoint
            }
          });
        }
      }
    })
  );
}